The present invention relates to an electrophotographic image forming apparatus, a process cartridge therefor, a developing device therefor, a developer supply container therefor and a measuring part.
Here, the electrophotographic image forming apparatus includes an electrophotographic copying machine, an electrophotographic printer, for example, an LED printer or laser beam printer, an electrophotographic printer type facsimile, an electrophotographic printer type word, or the like.
The process cartridge is a cartridge containing, as a unit, an electrophotographic photosensitive member and at least one process means which is a charging means, a developing means or cleaning means, or a cartridge containing, as a unit, an electrophotographic photosensitive member and at least developing means as process means, the process cartridge being detachably mountable to a main assembly of an electrophotographic image forming apparatus.
Heretofore, a process cartridge widely is used in an image forming apparatus using an electrophotographic image forming process, is a process cartridge which contains as a unit an electrophotographic photosensitive member and process means actable on the electrophotographic photosensitive member, which cartridge is detachably mountable to the main assembly of the electrophotographic image forming apparatus. Such process cartridge is advantageous in that a maintenance operation can be carried out in effect by the users. Therefore, this process-cartridge type is widely used in electrophotographic image forming apparatus.
With such an electrophotographic image forming apparatus of a process-cartridge type, the user is supposed to exchange the process cartridge, and therefore, it is desirable that there is provided means by which the user is notified of the consumption of the developer.
Heretofore, it is known that two electrode rods are provided in the developer container of the developing means, and the change of the electrostatic capacity between the electrode rods is detected to provide the amount of the developer.
Japanese Laid-open Patent Application No. HEI-5-100571 discloses a developer-detection electrode member comprising two parallel electrodes disposed on the same surface with a predetermined gap, in place of the two electrode rods, wherein the developer-detection electrode member is placed on the lower surface of the developer container. It detects the developer remainder by detecting the change of the electrostatic capacity between the parallel electrodes disposed on a surface.
Accordingly, it is a principal object of the present invention to provide an electrophotographic image forming apparatus, a process cartridge, a developing device, a developer-supply container, and a measuring part that is capable of detecting the remaining amount of the developer substantially in real-time.
It is another object of the present invention to provide an electrophotographic image forming apparatus, a process cartridge, a developing device, and a developer-supply container that is capable of detecting a remaining amount of the developer in the developer-accommodating portion substantially in real-time in accordance with the consumption of the developer.
It is a further object of the present invention to provide an electrophotographic image forming apparatus, a process cartridge, a developing device, and a developer-supply container that is capable of detecting a remaining amount of the developer using a change in the electrostatic capacity between electrodes, wherein measurement errors are attributable to changes of the ambient conditions, thus minimizing the detection error.
It is a further object of the present invention to provide a measuring part for detecting an amount of the developer substantially in real-time in accordance with the consumption of the developer in the developer-accommodating portion.
It is a further object of the present invention to provide a measuring part capable of detecting a developer remainder using a change of the electrostatic capacity between electrodes, wherein the measurement error is attributable to the changes of the ambient conditions, to accomplish detection of the amount of the developer with a small detection error.
According to an aspect of the present invention, there is provided an electrophotographic image forming apparatus, a process cartridge, a developing device, and a developer-supply container wherein there is provided a measuring part comprising an insulative substrate; a first electrostatic-capacity generating portion disposed at such a position that the first electrostatic-capacity generating portion contacts the developer accommodated in the developer-accommodating portion when a predetermined amount of the developer is accommodated in the developer-accommodating portion, the first electrostatic-capacity generating portion generating an electrostatic capacity corresponding to an amount the developer when the first electrostatic-capacity generating portion is supplied with a voltage, and a second electrostatic-capacity generating portion disposed at such a position that second electrostatic-capacity generating portion does not contact to the developer accommodated in the developer accommodating portion, the second electrostatic-capacity generating portion generating a reference electrostatic capacity when the second electrostatic-capacity generating portion is supplied with a voltage, wherein the first electrostatic capacity generating portion and the second electrostatic capacity generating portion are provided on the substrate.
According to another aspect of the present invention, there is provided an electrophotographic image forming apparatus, a process cartridge, a developing device, and a developer supply container wherein there is provided a measuring part comprising an insulative substrate; a first electrostatic-capacity generating portion including first electroconductive portions and second electroconductive portions alternatingly arranged in parallel with each other at regular intervals and a second electrostatic-capacity generating portion including third electroconductive portions and fourth electroconductive portions alternatingly arranged in parallel with each other at regular intervals, wherein the first electrostatic capacity generating portion and the second electrostatic capacity generating portion are provided on the insulative substrate.
According to a father aspect of the present invention, there is provided a measuring part comprising an insulative substrate; a first electrostatic-capacity generating portion disposed at such a position that the first electrostatic-capacity generating portion contacts the developer accommodated in the developer-accommodating portion when a predetermined amount of the developer is accommodated in the developer-accommodating portion, the first electrostatic-capacity generating portion generating an electrostatic capacity corresponding to the amount of the developer when said first electrostatic-capacity generating portion is supplied with a voltage, and a second electrostatic-capacity generating portion disposed at such a position that the second electrostatic-capacity generating portion does not contact to the developer accommodated in said developer-accommodating portion, the second electrostatic-capacity generating portion generating a reference electrostatic capacity when the second electrostatic-capacity generating portion is supplied with a voltage, wherein the first electrostatic-capacity generating portion and the second electrostatic-capacity generating portion are provided on the substrate.
According to a further aspect of the present invention, there is provided a measuring part comprising an insulative substrate; a first electrostatic-capacity generating portion including first electroconductive portions and second electroconductive portions alternatingly arranged in parallel with each other at regular intervals and a second electrostatic-capacity generating portion including third electroconductive portions and fourth electroconductive portions alternatingly arranged in parallel with each other at regular intervals, wherein said first electrostatic-capacity generating portion and the second electrostatic-capacity generating portion are provided on the insulative substrate.
These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.